// #650 timestamp producer's one-write invariant; prepared only.
import test from 'node:test';
import assert from 'node:assert/strict';
import fs from 'node:fs';
import { join } from 'node:path';
import { tmpdir } from 'node:os';
import { syncBuiltinESMExports } from 'node:module';
import * as markers from '../src/first-output.mjs';
function root(t){const p=fs.mkdtempSync(join(tmpdir(),'turn650-'));t.after(()=>fs.rmSync(p,{recursive:true,force:true}));return p;}
test('650 first-turn producer publishes time metadata only and keeps output content separate',t=>{const p=root(t);assert.equal(typeof markers.firstTurnMarker,'function','first-turn protocol producer exists');const before=process.hrtime.bigint();markers.firstTurnMarker(p)();const value=fs.readFileSync(join(p,'proxy-first-turn'),'utf8');assert.match(value,/^turn [0-9]+\n$/);const n=BigInt(value.trim().split(' ')[1]);assert.ok(n>=before&&n<=process.hrtime.bigint());assert.equal(fs.statSync(join(p,'proxy-first-turn')).mode&0o777,0o600);assert.deepEqual(fs.readdirSync(p),['proxy-first-turn']);markers.firstOutputMarker(p)('fx650-private-output');assert.equal(fs.readFileSync(join(p,'proxy-first-output'),'utf8'),'output\n');assert.equal(value.includes('fx650-private-output'),false);});
test('650 subsequent actual turn cannot reset or extend first timestamp',t=>{const p=root(t);assert.equal(typeof markers.firstTurnMarker,'function','first-turn one-shot producer exists');markers.firstTurnMarker(p)();const first=fs.readFileSync(join(p,'proxy-first-turn')),stat=fs.statSync(join(p,'proxy-first-turn'));markers.firstTurnMarker(p)();assert.equal(fs.readFileSync(join(p,'proxy-first-turn')).equals(first),true);assert.equal(fs.statSync(join(p,'proxy-first-turn')).mtimeMs,stat.mtimeMs);assert.deepEqual(fs.readdirSync(p),['proxy-first-turn']);});

// Narrow test-only filesystem interception, only this fixture's private prefix.
// Product has no injectable seam; every other file operation passes through.
for(const fault of ['partial write','exclusive collision','link','close','unlink'])test(`650 producer ${fault} failure keeps ownership and fixed diagnostic`,t=>{
 const p=fs.mkdtempSync(join(tmpdir(),'turn650-fault-'));let restore=()=>{};t.after(()=>{restore();fs.rmSync(p,{recursive:true,force:true});});assert.equal(typeof markers.firstTurnMarker,'function','guarded first-turn producer exists');
 const original=Object.fromEntries(['openSync','writeFileSync','linkSync','closeSync','unlinkSync'].map(k=>[k,fs[k]]));let fd,temporary,closeCalls=0,unlinkCalls=0,collisionCreated=false;
 const own=value=>typeof value==='string'&&value.startsWith(join(p,'.proxy-first-turn-'));
 restore=()=>{for(const [k,v] of Object.entries(original))fs[k]=v;syncBuiltinESMExports();};
 fs.openSync=function(file,...args){
  if(!own(file))return original.openSync.call(this,file,...args);
  temporary=file;
  if(fault==='exclusive collision'){
   const collisionFd=original.openSync.call(this,file,'wx',0o600);
   try{original.writeFileSync.call(this,collisionFd,'owned-collision');}
   finally{original.closeSync.call(this,collisionFd);}
   collisionCreated=true;
  }
  fd=original.openSync.call(this,file,...args);return fd;
 };
 fs.writeFileSync=function(file,data,...args){if(file===fd&&fault==='partial write'){original.writeFileSync(file,'t');throw Error('fx650-write-failed');}return original.writeFileSync.call(this,file,data,...args);};
 fs.linkSync=function(from,...args){if(own(from)&&fault==='link')throw Error('fx650-link-failed');return original.linkSync.call(this,from,...args);};
 fs.closeSync=function(value){if(value===fd){closeCalls++;const result=original.closeSync.call(this,value);if(fault==='close')throw Error('fx650-close-failed');return result;}return original.closeSync.call(this,value);};
 fs.unlinkSync=function(file){if(own(file)){unlinkCalls++;if(fault==='unlink')throw Error('fx650-unlink-failed');}return original.unlinkSync.call(this,file);};syncBuiltinESMExports();
 assert.throws(()=>markers.firstTurnMarker(p)(),error=>error.message==='first-turn marker publication failed','publication errors expose fixed diagnostic only');
 if(fault==='exclusive collision'){assert.equal(collisionCreated,true,'collision fixture created before product open');assert.equal(unlinkCalls,0,'collision does not confer temp ownership');assert.equal(fs.existsSync(temporary),true,'pre-existing collision not removed');assert.equal(closeCalls,0);}
 else {assert.equal(closeCalls,1,'owned descriptor close always attempted');assert.equal(unlinkCalls,1,'owned temporary unlink always attempted');if(fault!=='unlink')assert.equal(fs.existsSync(temporary),false);}
});